Braking mechanism



June 7,1921.

E. G. GARTIN BRAKING MECHANISM,

Filed March 21. 1921 Patented June 7 19. urnr g ELMER" r ce,

. MACHINERY COMPANY, A CORPORATION 0.1 MASSACHUSETTS.

' BRAKING MECHANISM.

Application filed March 21, 1921. Serial No. 454,103.

My invention relatesto braking mechanlsms and more particularly tobraking mechanisms for use inconnection with feeding mechanisms of thefluid pressure type. v

An object of my invention is to provide an improved braking mechanism.Another object of my invention is to provide an improved brakingmechanism for use in controlling the rate of feed of a feedingmechanism. A further object of nay-invention is to provide an improvedbraking mechanism for use in connection with that type offiuid pressurefeeding mechanisms "used with drilling motors. 'A still furtherobject ofmy invention is to provide an improved braking mechanism for controllingthe rate of feed of that type of drill motor known as a stoper. Otherobjects of my invention will appear in the course of the followingspecification and appended claims.

In the accompanying drawings; I have shown for purposes of illustration,one form which my invention'may assume in practice.

In these drawings Y Fig. '1 is a central longitudinal section throughthe feed cylinder of a drill motor in which 1s incorporated theillustrative form of my improvedbraking mechanism.

Fig. 2 is a-transverse section 'on theline 2 2 ofFig. 1. 7'

' For purposes of illustrati'on'I have disclosedflthe illustrativeembodiment of my improved braking mechanism used in con trolling thefeed of a rock drill of the type known as a stoper. In drills of thistype a percussive motor, whose rear end is illustrated at 1, is fed by'fluidpressurefeeding" mechanism generally indicated by 2. The feedingmeans comprises a cylinder 3 having a bore 4 in which a piston generallyindicated by 5 is reciprocable.

- The piston 5 herein is provided with a piston rod 6 which is in thepresent caseof hollow. construction having a bore 7 therein. The pistonrod passes through a bushing 8 closing the rear end of the bore 4 of thecylinder 3 and is provided at its lower end with a pointed projection9-adapted to enabut- 1 ment during drilling operation. Fluid gage therock or some other suitable pressure is admitted in a well known mannerunder the control of the valve 10, which also controls by well known;port means (not shown) the motor 1, by way of a' passage 11 to the frontend of the cylinderwhere it acts upon the piston 5 to force the cylinderforwardly wlth respect to the piston which is held stationary by re'asonof its abutment against the roclr or other stationary support. The pston 5 is of multi-pa'rt construction and comprises a member-12 providedwith an annular groove 13 in its periphery, in

which groove a pair of substantially sem1- 1 circular brake applyingmembers 14 are provided, these being in turn provided with plungers' '15which extend radially and which project at their inner ends into acylindrical bore 16 extending longitudinally through the piston 5. Thepistonalso comprises a packing securing ring 17 holding a cup packing 18of well-known form between it and the portion 12 ofthe piston. Sur-.rounding the members 14 and disposed in the groove 13 isa split band offriction material 20 which, when forced outward by the members 14,frictionally engages the bore 4 of the cylinder and tends to retard therelative movement of J the cylinder with respect to the piston. Suitablepackings 19 surround the plungers 15 and tend to preforcing thefriction' materialinto engage mentwith the cylinder bore. I Y

Extending longitudinally within the bore 7 of the piston rod 6. is amember 21 which is generally elliptical in cross section and which isprovided at its rear end with a vent air passing behind the members 14and r guide head 22 substantially fitting the bore I 7 of the pistonrod. This member 22 is provided with ports 23 to permit fluid pressureto pass to the opposite sides thereof; The member 21 extends through thebore 16,

formed on the piston and at its forwardend is slightly reduced indiameter and turned to circular shape as indicated at 25,=therebyproviding .a shoulder 24= -which engages against a stationary shoulder26 surrounding the portionf25. Asuitable packing 27 surrounds theportion 25 of the member 21 and prevents leakagev of air out of the forward end of the cylinder. The. reduced portion 25 of the member 21 ismade polygonal at its forward end and a suitable handle 28 projectingthrough a slot 29 in the side wall of a chamber 30-interposed betweenthe front end of. thefeed cylinder and the rear end of the motor 1 isattached to the polygonal portion of the member 21 It will be noted fromFig. 2 that, when the member 21 lies in such an inspection of 1 yrelation to the plungers that its minor axis is in alinement with theaxes of these plungers, the plungers do not force out the packing infrictional contact with the bore 4: ofthe cylinder and accordingly thecylinder is free to move in respect to the piston without brakingaction. When, however,

the handle 28 is turned in either direction from its position shown inFigs. 1 and2, it Will be evident that the .member 21 acts as a cam andthat irrespective of the position of the feed cylinder relative to thepiston, the plungers 15 will be forced. outwardly and the packingmaterial will fric- Vtionall-y engage the bore 4 of the cylinder 3mechanism is shown at 34.

It will be obvious vthat the piston rod 6 must be maintained unvaryingrelation, as respects rotation, to the cylinder 3 and accordingly I haveprovided, by brazing, riveting, or any suitable means, a spline 30extending longitudinally thereof and engaging in a groove '31 formed inthoclosure bushing 8 at the rear .end of a cylinder 3. Theusual vent 33is provided in the wall of the cylinder 3, and any air which gets behindthe packings is permitted to escape to a space communicating with thisvent by ports 32.

From the foregoing description it will be obvious that I have providedbraking mechanism of a type which is very convenient to operate in thatthe .control lever is mounted at one end of the cylinder and in fixedrelation to tllGsillll'OttlG valve 10 whereby the operator may readilymove his hand be *tween the control means used in the operation of thedrill. It will also be obvious that by reason of the improvedconstruction, the efficiency of the braking means does not vary frompoint to point of the cylinder, but that the connection provided is suchas to permit the control of the brake irrespective of the'relativepositions of piston and cylinder. 7

lVh'i le I have in this application specifically described one formwhich my invention may assume in practice, it will be understood thatthis form 0f the same is used for purposes of illustration and that theinvention may be embodied in various other forms without departing fromits'spiri't or the scope of the appended claims.

' What "claim new and desire ito secure by Letters Patent is: I

1. Feeding mechanism comprising, in comnation, a stationa y bination,stationary and movable members cooperating to form an expansible chamberfeeding motor, means carried by one of said members and f-rictionallyengageable with the other, and means-carried by the other of saidmembers for controlling said frictional engaging means.

:2. F eedingmechanism comprising, in combin-ation, relatively stationaryand movable members cooperating to form an eXpansible chamber feedingmotor, means carried by' one of said members and. frictionallyengageable with the other to retard such relative movement, and meanscarried by the other of said members for mechanicallycontrolling saidfrictional engaging means.

3. Feeding mechanism comprising, in combination, stationary and movablemembers cooperating to form. an expansible chamber feeding motor,braking means carried by the stationary member, and means forcontrolling the braking means carried by the movable member. V

I 4. Feeding mechanism comprising in combination, stationary and movablemembers cooperating to form an expansible chamber feeding motor, brakingmeans for said movable member carried by said stationary renderingeffective the frictional engaging means. a

6. Feeding mechanism ooiiapi'ising, in combination, a stationary member,a member movable relative thereto, said members 00- perating to form anexpansible chamber feeding motor, a member carried by the stationarymember and adapted frictionally to engage the moving member, andrelatively rotatable @means carried by the movable member for renderingeffective the frictional engaging means.

7.- Braiking means comprising, in combimember, a movable member,saidwmembers cooperating to form an ezq a nsiblev chamber feeding motor,fric-, tional braking means carried by the stationary member, operatingmeans for the fri,c

. tiona'l i braleing means carriedby the movable member and disposedWithin the periphery .of-the. stationary member, and means v:fion

controlling the operating means.

gaging the bore of the cylinder, means extending longitudinally throughthe piston for rendering said frictional engaging means operative, andcontrolling means for said last mentioned means carried by the cylinder.p

10. Feeding mechanism comprising, in combination, a cylinder, a pistontherein, means carried by the piston for frictionally engaging the boreof the cylinder, and means extending longitudinally through the pistonfor rendering said frictional engaging means operative rotatable aboutan axis parallel to a line parallel to the axis of said I cylinder.

cam means cooperating therewith and extending through the piston, andmeans for controlling the last mentioned means.

12. Feeding mechanism comprising, combination, a cylinder, a pistontherein, a brake band carried by one of said members, means for directlyapplying said brake band carriedby said last mentioned member, andmeanscarried by the other of said members for causing operation of said brakeband applying means, said means being coaxially arranged with both ofsaid members.

13. Feeding mechanism comprising, in combination, a movable cylindermovable to effect feeding of the device to be fed, a stationary piston,and radially expansible means carried by said piston for restraining themovement of said cylinder.

14. Feeding mechanism comprising in combination, cooperating relativelylongitudinally movable elements cooperating to form an expansiblechamber feeding motor,

and cam operated means for controlling the movement thereof,said meansbeing located within one of said elements and having controlling meanstherefor carried by the other element. 1

15. Feeding mechanism comprising, in combination, a cylinder and apiston having relative movement, and cam operated means carried by saidpiston for restraining movement of said cylinder.

16. Feeding mechanism comprising, in

combination, a movable cylinder movable.

during feed with the device to be fed having a bore formed therein, astationary piston disposed in said bore, and means for frictionallyengaging the surface of said bore for restraining movement of saidcylinder.

17. Feeding mechanism comprising, in

combination, stationary and movable members cooperating to form anexpansible chamber feeding motor, radially expanding braking meanscarried by said stationary member, and means carried by said movablemember for varying the capacity of the radially expanding braking means.

18. Feeding mechanism comprising, combination, a stationary member and amovable member cooperating to form an expansible chamber feeding motor,means carried by said stationary member for frictionally engaging saidmovable member, and controlling means carried by said movable member forapplying said frictional means.

19. In a drilling mechanism, in combination, a drilling motor, pressurefluid feeding means therefor including a movable cylinder and astationary piston, means for control ling. the pressure fluid supplythereto, means carried by said piston for restraining the movement ofSL1Cl cylinder, and means movable with said cylinder for varying thecapacity of said feed restraining means.

20. In a drill mechanism, in combination, a drilling motor, pressurefluid feeding means therefor including a stationary and a movablemember, restraining means for said feeding means carried by saidstationary member, and means movable with said drilling motor forcontrolling the pressure fluid supply of the feeding means and thecapacity of the feed restraining means.

In testimony whereof I affix mysignature.

ELMER c, GARTIN.

